The present invention relates to a primary-cell of the type in which a cathode or anode expands its apparent volume as the discharge proceeds, thereby absorbing therein the electrolyte.
The typical anode and cathode of the above characteristic is a cathode which mainly consists of fluorinated carbon or silver chromate and is used in an organic electrolytic solution, and a zinc anode used in an alkaline electrolytic solution in mercuric oxide cells, alkaline-manganese cells, and silver oxide cells. In these prior art cells, in order to prevent the expansion of a cell enclosure and to keep the electrolyte, between a cathode and anode are interposed not only a separator but also a cotton-fiber spacer which may keep the electrolyte and may reduce its apparent volume when the pressure is applied thereto. The spacer serves as a cushion for absorbing the pressures produced in the primary-cell due to the expansion of the cathode or anode. As the apparent volume of the spacer is reduced, the electrolyte kept or absorbed thereby is squeezed out of it into the cathode or anode. As a result, the electrolyte in the spacer decreases as the discharge proceeds so that the ion conduction between the cathode and anode is adversely affected. In the cells of the type employing an organic electrolyte (consisting of, in general, an electrolyte consisting of a material selected from the group consisting of inorganic salts of light metals and dissolved into an organic solvent) whose conductivity is considerably smaller than that of an aqueous electrolyte, the above drawback is pronounced considerably. As the result, the internal resistance of the primary-cell increases considerably with the decrease in volume of electrolyte in the spacer. Furthermore, the interposition of the spacer between the cathode and anode inevitably results in a longer spacing therebetween so that the internal resistance is further increased. Therefore, the prior art cells have a low capacity, and cannot make full use of the active materials.